FAMILIA MÉXICO Y SONORA EN CIFRAS
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Table 2.5-3 summarises the impact on the demand used in assessment for each of the abnormal operations scenarios defined above33:
Table 2.5-3 Demand assumptions for abnormal operations Operational
scenario
Implication for passenger demand
Service
Perturbation (Cat A-C stations)
Passengers entering the station should be assumed to continue to do so during the period of service perturbation and accumulate on the platforms or concourses depending on the station (unless station management plans specifically make alternative arrangements). Following the period of the perturbation, passengers will board the trains according to the capacity available (and the destinations of following train services) – it may take several trains to clear the backlog for busy stations.
The trains arriving at each platform after the end of the period of perturbation will do so at the minimum headway permissible by the signalling system (taking into account platform dwell times) until normal service is resumed.
Service Passengers entering the station should be assumed to continue to do so and accumulate on the
31
In an evacuation, escalators should be assumed to continue to operate in the direction they were doing before the evacuation started. Where an escalator is stationary, it should be assumed to operate with the same capacity as a fixed stairway.
32
Apart from during evacuation where the gates will be open, it depends on gateline strategy and crowd control plan and how the station wants to handle revenue protection in abnormal circumstances
33
Table 2.5-3 Demand assumptions for abnormal operations Operational
scenario
Implication for passenger demand
Perturbation (Cat D-F stations)
platforms (unless the station management plans specifically make alternative arrangements). Passengers will board the trains arriving following the cancelled service according to the capacity available (and the destinations of following train services) – it may take several trains to clear the backlog, as the cancelled train may have a significant impact upstream of the station in question.
The trains arriving at the platform after the cancelled train will be more heavily loaded, so train arrival loads will have to be increased until the impact of the cancellation is no longer felt. Train on Fire
Evacuation
The evacuation load should be assumed to include the following:
Occupancy at time of evacuation should be based on peak usage with 5 minute delay to the scheduled train service in the busiest direction only
In addition to the above all occupants of a crush-loaded train (on fire), plus those normally expected to alight from the next train in the other direction or any other lines34
All exit routes can be counted as available for use and escalators continue to run as before the emergency
Passengers cannot pass along the platform or through the train past the source of the fire Anybody else within the station that will need to be evacuated in accordance with the station fire evacuation plan.
Station on Fire Evacuation35
The evacuation load should be assumed to include the following:
Occupancy at time of evacuation should be based on peak usage with 5 minute delay to the scheduled train service in the busiest direction only
The exit route with the greatest capacity should be discounted (as it could be blocked by fire) Passengers waiting to board plus those normally alighting from the next train in each direction should be evacuated
2.5.3
Abnormal situation
2.5.3.1
Emergency Evacuation
Station evacuation – where everyone within the station (or part of the station) has to be evacuated. Station design should take into account the following two emergency “worst case” scenarios:
1. Train on fire in station.
In this case, the evacuation load (the platform and train loads) should be clear from the immediate area (the platform) within four minutes and should reach a fire protected route within six minutes if the platforms are underground. Surface station platforms should be evacuated in a maximum of eight minutes and the whole station should be evacuated in no more than twelve minutes
2. Fire within the station structure.
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If it can be demonstrated that trains arriving at the station are never crush loaded (for example, at the “country” end of commuter lines), the load of the busiest train on the traffic day should be used. This load should be doubled to take account of a previously cancelled service.
35
Evacuation scenarios should be defined on a station by station basis and in consultation with the stations fire evacuation plan and Network Rail.
Surface station platforms should be evacuated in a maximum of eight minutes and the whole station should be evacuated in no more than twelve minutes.
2.5.3.2
Perturbation
Service perturbation is defined as a significant delay to the service leading to increased waiting in the station environment (either on the platforms or the concourses)36. The definition (and indeed the impact) of service perturbation varies on a station by station basis. As a generalisation, however, perturbation can be defined as follows:
For category A, B, or C stations (or for lower category stations where the train service is 4 trains per hour or greater), a service perturbation represents a complete cessation of train services for a fifteen minute period (it may only affect a certain service group if services are bundled together, for example rail services into Waterloo are divided into suburban, main line and Windsor Line
services). For the purposes of assessment of station performance, the busiest fifteen minute period should be used.
For category D, E, or F stations, a service perturbation represents a complete cancellation of a train service. For the purposes of assessment of station performance, the busiest train service should be assumed to be cancelled.
During perturbation station management follows the procedures outlined in their crowd management plan. The crowd management plan details a number of levels with controls for each level.
As an example, at Waterloo, the three most serious levels, where Network Rail starts to put physical control measure in place are as follows (bearing in might that it might not affect the whole station but one side of it):
Level 3 (15-30 minute delays with probably recovery):
No obvious movement of people other than in area three meters from building walls Potential Opening of gates due to barrier line congestion (with loss of revenue) Removal of retail seating areas
Stop/reverse escalators to slow number of passengers coming onto concourse
36
A service perturbation in this context refers to a significant disruption, it is acknowledged that minor delays happen frequently, and should be considered as part of “normal” operations.
Level 4: 30-59 minutes delay where recovery is unknown
As above plus:
Call BTP for assistance above normal provisions
Contact LUL/Waterloo East to ask that they be ready to not permit to stop in Underground/Waterloo East
Potential Closure of Exit 4
Level 5/6: > 60 minute delay - evacuation
As above plus:
Preparation for/ deliver partial or full evacuation
Whether a perturbation scenario is required or not should be agreed with the project team first and the outcome of the perturbation analysis should be discussed with the project team and station management. In most cases the existing crowd management plans can be changed to reflect the impact the proposal has on crowd control, i.e. one result could be that a proposal has led to a smaller sized concourse and a direct result of this is that the concourse now fills up quicker during perturbation than it has been previously the case. As a consequence the crowd management plan needs to be amended in a way that the different levels kick in earlier.
In terms of what time period should be assessed, on London termini the worst time period for perturbation is likely to be in the PM peak. On a through platform the worst time period could be an AM peak when passengers are accumulating on the platforms.
If the planning requirements above cannot be fulfilled a risk assessment should be carried out.
2.5.3.3
Construction
Station construction is defined as a situation where elements of the station are under construction for a finite period of time leading to the required passenger space being compromised.
Depending on the size of the station and the impact the various construction stages have on passenger flows, it will be necessary to assess what exactly the impact is and how it can be mitigated should it cause problems.
The requirements of a construction assessment should be discussed with the project team, station management and the Senior Station Capacity Specialist.
Level 5/6: no pictures exists
In terms of what time period should be assessed, on a London terminus the worst time period for assessing construction impact on a concourse is in the PM peak. If the construction site is on the platforms then the worst peak would be the AM peak. On a through platform the worst time period could be an AM peak when passengers are accumulating on the platforms.
2.5.3.4
Special Events
Special events are events taking place in the vicinity of the station that lead to a temporary increase in station patronage.
Crowds, or large concentrations of people, occur frequently near major sporting or entertainment venues. A major sporting or entertainment event can attract around 70,000 avid fans depending on the size of the venue. Large transportation terminals such as Waterloo and Victoria Station accommodate around 300,000 passengers each weekday.
It is difficult to describe the psychological and physiological pressures within crowds at maximum density. When crowd density equals the plan area of the human body, individual control is lost, as one becomes an involuntary part of the mass. At occupancies of about 7 persons per square meter the crowd becomes almost a fluid mass.
Although the terms crowd management and crowd control are often used interchangeably, there are important differences. Crowd management is defined as the systematic planning for, and supervision of, the orderly movement and assembly of people.
Crowd control is the restriction or limitation of group behaviour. Crowd management involves the assessment of the people handling capabilities of a space prior to use. It includes evaluation of projected levels of occupancy, adequacy of means of ingress and egress, processing procedures such as ticket collection, and expected types of activities and group behaviour.
Architects and engineers typically give minimal attention to the movement of people in initial building design, beyond compliance with local building codes. Code compliance does not guarantee that a building will function well during normal assembly use or emergency egress. Designing for crowd management requires that projected maximum occupancy levels of a space be correlated with the movement capabilities of all corridors, stairs, ramps, escalators, and other facilities. For stations near a stadium or similar crowd attracting venue, station management will have to prepare a crowd management plan. The plan should establish the assembly and people movement capabilities of all aspects of the venue, movement patterns, identify possible problem areas, and generally describe how the design will accommodate normal and emergency crowd movement. Flow capacities of corridors, stairs, passenger conveyors, and waiting spaces, have been established by a number of sources37
. The scope should clearly state if special events need to be considered as part of the assessment since a passenger count will need to be carried out on a special event day. These may not take place regularly and waiting for an event to happen could have an impact on the programme.
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Volume Two: Station Capacity Assessment Guidance
3.1 Introduction
The purpose of Volume Two is to provide guidance to project managers and consultants and other interested parties responsible for scoping and producing station capacity assessment studies.
The aim of this document is to ensure a consistent and acceptable approach when undertaking station capacity assessment studies, so that everybody involved in station capacity assessments understands what is required in terms of approach, analysis and documentation.
Volume Two covers the following:
The objectives of undertaking a station capacity assessment The recommended approach to carrying out a capacity assessment When to carry out a static or dynamic modelling
Data requirements, and the means for collecting data The scenarios to be tested
How to carry out a static analysis How to carry out dynamic modelling
Validating and Auditing analysis or model outputs Interpretation of model outputs
Deliverables and Documentation